1. Field of the Invention
The present invention relates to a device for generating X-rays, and more particularly to an X-ray tube for generating X-rays linearly focused in a vertical or horizontal direction in accordance with the orientation of a filament used.
2. Description of the Related Art
Conventional X-ray tubes typically use an anode made of a particular material suitable to generate desired X-rays in cooperation with a spiral filament. When a high voltage is applied to the anode made of the particular material, thermoelectrons are emitted from the filament. By virtue of the effect of those thermoelectrons, two kinds of X-rays, that is, X-rays emitted from the particular material and continuous X-rays resulting from a bremsstrahlung effect are generated. Meanwhile, it is frequently required to generate line-focused X-rays. For the generation of such line-focused X-rays, conventional X-ray tubes may utilize a very fine and sophisticated slit. In this case, however, undesirable fluorescent X-rays may be generated due to the material of the slit. Furthermore, there is a reduction in the intensity of X-rays.
Therefore, the present invention has been made in view of the above mentioned problems involved in the conventional X-ray tubes, and an object of the invention is to provide an X-ray tube which does not use a spiral filament, but uses a linear filament, thereby generating X-rays linearly focused in a vertical or horizontal direction in accordance with the orientation of the linear filaments.
Another object of the invention is to provide an X-ray tube capable of line-focused X-rays without using no fine and sophisticated slit.
In order to accomplish the above mentioned objects, the present invention provides an X-ray tube comprising: a linear filament arranged at a cathode included in the X-ray tube, the linear filament serving to allow an anode included in the X-ray tube to generate line-focused X-rays.